Er... except for the space operas, and many genre crossovers like SF mysteries. And things like FTL drives or wormholes as accepted shortcuts for getting your characters around space, or impossible planetary set-ups. And much of the military SF tradition. And any science fiction whose themes aren't about the technology or the science -- even if you choose to include the soft sciences -- but are about some other aspect of society or humanity.

Any definition of SF that sounds to me like it excludes Dune* has a problem.


* not due to any specific fondness I have for the book, but because it's so much an accepted cornerstone of SF.